The present invention relates to an aqueous dispersion of a degradable resin composition, which is prepared by dispersing and stabilizing in water an essential composition comprising a base polymer that consists substantially of a water-insoluble starch-type, biodegradable resin, and optionally a plasticizer, a filler, an antioxidant, a stabilizer, a dispersant, an emulsifier, a thickener and a solvent.
It relates to an aqueous dispersion of a biodegradable resin composition with good handlability, which is thermoplastic and biodegradable and which is used in various fields of papermaking, non-woven fabric production, film and sheet production and woven fabric production, in those of dispersed adhesive production, and in those of metal processing, plastic processing, wood processing and stone processing.
With various environmental problems being much discussed, materials good to the environment, such as typically various biodegradable plastics and processed paper, and applicable to the field where synthetic polymers have heretofore been used are being studied and developed. In particular, the applications of those materials to laminates and films are being much studied. Where such biodegradable plastics are used in producing laminates and films, extruders are used for extrusion lamination. In addition, used are techniques of melt spinning and injection molding of resins. In those techniques, resins are generally used as their hot melts.
In other embodiments of using conventional synthetic resins including biodegradable resins, used are synthetic emulsions as prepared through emulsion polymerization, such as typically synthetic rubbers and polyvinyl acetate resins, and also hot melts of resin compositions as prepared by hot-melting resins, typically polyvinyl acetate resins along with paraffins.
Where polyvinyl chloride resins and the like are used, they may be dispersed in plasticizers or organic solvents to give plastisols and organosols.
In those conventional cases, resins are melted under heat, or emulsified during their production, or organic solvents (including plasticizers) are used. No one knows an aqueous dispersion consisting indispensably of a thermoplastic biodegradable resin, which is prepared by dispersing and stabilizing a powder of the resin itself in water, and even knows that the dispersion can be applied onto substrates or can be cast onto substrates for bonding those substrates through vaporization of water, or the dispersion can be used for processing substrates themselves or their surfaces, or the dispersion can be formed into films, sheets, plates and others through casting.
The object of the present invention is to provide an aqueous dispersion of a biodegradable resin composition with biodegradability and thermal decomposability and with good handlability, which is prepared by dispersing and stabilizing in water a thermoplastic, biodegradable resin composition optionally along with additives, and which is used in various fields of papermaking, non-woven fabric production, film and sheet production and woven fabric production, in those of dispersed adhesive production, and in those of metal processing, plastic processing, wood processing and stone processing.